Technique of suppressing influence of contamination of exposure atmosphere

ABSTRACT

An exposure apparatus includes a projection optical system which has a plurality of optical elements, and directs light from an original to an object to be exposed; a first stage which holds the object to be exposed; a first vacuum chamber which contains the first stage; and a second vacuum chamber which is adjacent to the first vacuum chamber, contains a part of the plurality of optical elements, and communicates with the first vacuum chamber through a first opening. The pressure in the second vacuum chamber is higher than pressure in the first vacuum chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the technique of suppressing the influence ofthe contamination of exposure atmosphere, which is suitable for use inthe manufacture of a device having a fine pattern such as semiconductordevices.

This invention is particularly suitable for an exposing apparatus foreffecting exposure by the use of light of a short wavelength (0.5 to 50nm) like EUV light, or an exposing apparatus for effecting exposureunder a high vacuum atmosphere by the use of an optical element such asa mirror or a lens.

2. Description of Related Art

In recent years, in the optical lithography technique for manufacturingsemiconductors, the shortening of the wavelength of exposure light hasbeen advanced and progress has been made from i-line and g-line to KrFexcimer laser and ArF excimer laser. If the shortening of the wavelengthof exposure light progresses, it will become possible to transfer aminuter mask pattern to a wafer. However, to exposure a pattern of athin line width, lithography using ultraviolet light is limited inprinciple. So, EUV lithography using extreme ultraviolet light (EUVlight, 13 to 20 nm) of a shorter wavelength than ultraviolet light hasbeen drawing attention.

A typical wavelength used in the EUV light is 13.5 nm and therefore, itis possible to realize resolution for exceeding that of the opticallithography hitherto, on the other hand, the EUV light has the naturethat it is readily absorbed by substance. Therefore, if reductionexposure using a refractive optical system is effected as in theconventional lithography using ultraviolet light as a light source, theEUV light will be absorbed by a glass material and the quantity of lightreaching a member to be exposed such as a wafer will become extremelysmall. Therefore, when exposure is to be effected by the use of the EUVlight, it is necessary to configure reduction exposure using areflecting optical system.

FIG. 4 is a schematic view of a conventional reduction projectionexposing apparatus using the EUV light (see Japanese Patent ApplicationLaid-Open No. 2003-45782). An EUV exposing apparatus 200 has an EUVlight source 210, an illuminating optical system 220, a reticle (mask)230, an alignment optical system 240, a reticle stage 250, a wafer stage260, a wafer 270, a vacuum container 280, a reflection type reductionprojection optical system 100, a first mirror 110, a second mirror 120,a third mirror 130, a fourth mirror 140, a fifth mirror 150 and a sixthmirror 160, and is also provided with an exhausting system, not shown,for exhausting gas in the vacuum chamber 280, etc.

There are several kinds of EUV light source, and a laser producingplasma light source which is one of them can emit light of only asubstantially necessary wavelength band by the selection of a targetmaterial. When for example, Xe is ejected as a target material from apulse nozzle, and a pulse laser is applied thereto to thereby generateplasma, EUV light of a wavelength 13-14 nm is emitted.

The illuminating optical system is comprised of a plurality ofmulti-layer film mirrors, an optical integrator, etc. As the roles ofthe illuminating optical system, mention may be made of efficientlycondensing light emitted from the light source, and uniformizing theilluminance in an exposure area. Also, the optical integrator has therole of uniformly illuminating the mask at a predetermined numericalaperture.

The projection optical system is comprised of a reflecting opticalsystem using a multi-layer film mirror alternately coated with Mo andSi. This Mo/Si multi-layer film can obtain normal-incidence reflectanceof the order of 67% in the vicinity of a wavelength 13 nm. It isdifficult in principle to provide reflectance of 100% and most ofabsorbed energy changes into heat. Therefore, low thermal expansionglass or the like is used for the base material of the mirror. In thereflecting optical system, a plurality of such Mo/Si multi-layer filmmirrors are used for aberration correction, however, to keep thetransmittance of the EUV light, it is necessary to minimize the numberof the multi-layer film mirrors.

The reticle stage and wafer stage of the EUV exposing apparatus havemechanisms for driving under a vacuum environment, and the reticle stageand the wafer stage scan in synchronization with each other at a speedratio proportional to a reduction magnification. Also, the positions andpostures of the reticle stage and the waver stage are observed andcontrolled by a laser interferometer, not shown.

A reticle held by a reticle chuck and a wafer held by a wafer chuck arehighly accurately positioned by fine motion mechanisms carried on thereticle stage and the wafer stage.

The alignment optical system is an apparatus for detecting thepositional relation between the position of the reticle and the opticalaxis of the projection optical system, and the positional relationbetween the wafer and the optical axis of the projection optical system.Thereby, the positions and angles of the reticle stage and the waferstage are set so that a projected image may be applied to apredetermined position on the wafer. Also, a focus position in adirection perpendicular to the surface of the wafer is detected by afocus detecting mechanism, and the position and angle of the wafer stageare controlled, whereby the imaging position on the surface of the waferis always kept.

In order to avoid the absorption of the EUV light by substance, it isnecessary that the space, to which the EUV light of the EUV exposingapparatus, is to be kept in vacuum. Therefore, a plurality of exhaustsystems such as vacuum pumps are mounted on the exposing apparatus.

The EUV light used in the EUV exposing apparatus is absorbed by theatmosphere in the apparatus. Particularly, oxygen and moisture stronglyabsorb the EUV light. Therefore, to keep the transmittance of the EUVlight high, it is necessary to render the interior of a chamber into avacuum state by the utilization of a vacuum pump or the like. It isdesirable that the pressure in the chamber through which the EUV lightpasses be 10⁻3 Pa or less and the partial pressure of oxygen andmoisture be infinitely low. However, some of moisture adhered to thewafer during the conveyance of the wafer is diffused in the chamber.Further, moisture is liable to adhere to the inner wall of the chamberand is difficult to be exhausted. The adherence of moisture to theoptical element becomes a cause of the oxidization of the opticalelement and the reduction of the reflectance of the optical element.

Also, when the interior of the chamber becomes a vacuum state,hydrocarbon is produced from the mechanism portions of the stages or thelike. Further, reaction of resist by the exposure light during exposurealso produces hydrocarbon, and when such hydrocarbon is applied to theexposure light on the surface of the optical element, it adheres ascarbon to the surface of the optical element. The carbon adhered to theoptical element absorbs the EUV light and reduces the reflectance of theoptical element. The reduction of the reflectance of the optical elementleads to a reduction in throughput.

Thus, particularly in the space where the optical element in the EUVexposing apparatus is installed, the partial pressure of moisture andhydrocarbon need be kept low.

To lower the partial pressure of moisture and hydrocarbon or the like inthe exposing apparatus, the step of enhancing the capability of theexhaust system such as a vacuum pump is also effective. However, it isinevitable that the moisture adhering to the conveyed wafer and thehydrocarbon produced from the resist and the mechanism portions of thestages drift in the space, where the optical element is installed, dueto diffusion and therefore, it is difficult to improve the throughput.

Also, at present, regarding the manufacture of semiconductor devicessuch as DRAM and MPU, research and development are being energeticallymade to realize a device having a line width of 0.1 μm or less in termsof the design rule. As an exposing apparatus for use in this generation,an exposing apparatus using the extreme ultraviolet light (EUV) isregarded as being potent. Since in the EUV exposing apparatus, exposurein the atmosphere is impossible, exposure cannot help being effected invacuum.

In the EUV exposing apparatus, particles are produced by slidingmovement and friction such as the operations of a robot hand and a gatevalue until a reticle and a wafer are conveyed to an apparatus chamber,and there has been the possibility of these particles adhering to thereticle and the wafer. Also, there has been the possibility thatparticles produced from movable portions such as stages and the like mayadhere to the surfaces of the reticle and the wafer during exposure.

Such adherence of the particles to the surfaces of the reticle and thewafer has caused the problem the yield of the manufacture of the deviceand the reliability of the device are lowered. Particularly, if theparticles adhere to the circuit pattern surface of the reticle, theparticles will be transferred to the entirely same position at each shotin actual exposure. This has led to the problem that the yield of themanufacture of the device and the reliability of the device are greatlylowered.

SUMMARY OF THE INVENTION

The present invention has as its illustrative object to solve at leastone of the above-mentioned problems of the prior art.

In order to achieve the above object, the present invention is providedwith the following aspects.

According to the present invention, the above object is attained byproviding an exposure apparatus which comprises a projection opticalsystem having a plurality of optical elements and directing light froman original to an object to be exposed, a first stage which holds theobject to be exposed, a first vacuum chamber which contains the firststage, and a second vacuum chamber which is adjacent to the first vacuumchamber, contains a part of the plurality of optical elements, andcommunicates with the first vacuum chamber through a first opening,wherein pressure in the second vacuum chamber is higher than pressure inthe first vacuum chamber.

Further, the above object is also attained by providing an exposureapparatus which comprises a projection optical system which has aplurality of optical elements and directing light from an original to anobject to be exposed, a first stage which holds the original, a firstvacuum chamber which contains the first stage, and a second vacuumchamber which is adjacent to the first vacuum chamber, contains a partof the plurality of optical elements, and communicates with the firstvacuum chamber through a first opening, wherein pressure in the secondvacuum chamber is higher than pressure in the first vacuum chamber.

According to the present invention, there can be provided a technique ofsuppressing the influence of the contamination of exposure atmospherewhich is suitable for use in the manufacture or the like of a devicehaving a minute pattern such as a semiconductor device, and particularlythe technique suitable for an EUV exposing apparatus or an exposingapparatus for effecting exposure under a high vacuum atmosphere by theuse of an optical element.

Other objects and advantages than those discussed above will be apparentto those skilled in the art from the following description of preferredembodiments of the invention. In the description, reference is made tothe accompanying drawings, which form a part thereof, and whichillustrate an example of the invention. Such example, however, is notexhaustive of the various embodiments of the invention, and therefore,reference is made to the claims which follow the description fordetermining the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an EUV exposing apparatus according to afirst embodiment of the present invention.

FIG. 2 shows the transition of the partial pressure of hydrocarbon inthe first embodiment.

FIG. 3 is a schematic view of an exposing apparatus according to asecond embodiment of the present invention.

FIG. 4 is a schematic view of a conventional EUV exposing apparatus.

FIG. 5 is a flow chart for illustrating the manufacture of a device (asemiconductor chip such as IC or LSI, an LCD, a CCD or the like).

FIG. 6 is a detailed flow chart of the wafer processing of a step 4shown in FIG. 5.

FIG. 7 is a schematic view of an EUV exposing apparatus according to afourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some embodiments of the present invention will hereinafter be describedin detail with reference to the accompanying drawings.

(First Embodiment)

FIG. 1 shows a first embodiment of an exposing apparatus (exposureapparatus) using the EUV light (herein light of a wavelength of 0.1 to30 nm, and preferably 10 to 15 nm) of the present invention.

In FIG. 1, the reference numeral 8 designates EUV light emitted from anEUV light source and directed by an illuminating optical system, notshown, and this EUV light 8 is applied to a reticle through theintermediary of a reticle illuminating mirror 1. The reference numeral 2denotes a projection system first mirror, the reference numeral 3denotes a projection system second mirror, the reference numeral 4denotes a projection system third mirror, the reference numeral 5denotes a projection system fourth mirror, the reference numeral 6denotes a projection system fifth mirror, the reference numeral 7denotes a projection system sixth mirror, the reference numeral 11denotes a reflection type reticle, the reference numeral 12 denotes areticle chuck, the reference numeral 13 denotes a reticle stage, thereference numeral 14 denotes a reticle alignment optical system, thereference numeral 21 denotes a wafer, the reference numeral 22 denotes awafer chuck, the reference numeral 23 denotes a wafer stage, and thereference numeral 24 denotes a wafer alignment optical system.

There are several kinds of EUV light sources, not shown, and a lasergenerating plasma light source, which is one of them, can emit light ofonly a substantially necessary wavelength band by the selection of atarget material. When for example, Xe is ejected as a target materialfrom a pulse nozzle, and a pulse laser is applied thereto to therebygenerate plasma, EUV light of a wavelength 13-14 nm is emitted.

The illuminating optical system, not shown, is comprised of a pluralityof multi-layer film mirrors, an optical integrator, etc. As the roles ofthe illuminating optical system, mention may be made of efficientlycondensing light emitted from the light source, and uniformizing theilluminance of an exposed area. Also, the optical integrator has therole of uniformly illuminating a mask at a predetermined numericalaperture.

The projection optical system is comprised of a plurality of multi-layerfilm mirrors alternately coated with Mo and Si. This multi-layer filmhas normal-incidence reflectance of the order of 67% for the EUV lightand therefore, most of energy absorbed by the multi-layer film mirrorschanges into heat. Therefore, low thermal expansion glass or the like isused as the base material of the mirrors.

The reticle stage 13 and the wafer stage 23 have mechanisms for drivingunder a vacuum environment, and scan in synchronization with each otherat a speed ratio proportional to a reduction magnification. Also, thepositions and postures of the reticle stage 13 and the wafer stage 23are observed and controlled by a laser interferometer, not shown.

The reticle 11 is held by the reticle chuck 12 on the reticle stage 13.Also, the wafer 21 is held by the wafer chuck 22 on the wafer stage 23.The reticle stage 13 and the wafer stage 23 have fine motion mechanisms,and can position the reticle 11 and the wafer 21, respectively.

The alignment detecting mechanisms 14 and 24 measure the positionalrelation between the position of the reticle and the optical axis of theprojection optical system, and the positional relation between the waferand the optical axis of the projection optical system, respectively. Onthe basis of the result of the measurement, the positions and angles ofthe reticle stage 13 and the wafer stage 23 are adjusted so that theprojected image of the reticle may coincide with a predeterminedposition on the wafer.

Also, the focus position detecting mechanism 24 detects a focus positionin a vertical direction on the surface of the wafer to keep the imagingposition of the projection optical system on the surface of the wafer.

When one cycle of exposure is terminated, the wafer stage 23 isstep-moved in X and Y directions, and is moved to the start position ofthe next scanning exposure and effects exposure again.

In this first embodiment, there is adopted a configuration in which aspace including therein the projection optical system disposed betweenthe reticle and the wafer is separated into a first projection systemspace 62 and a second projection system space 63, and an orifice member52 is interposed between the two spaces, whereby a pressure differencecan be produced between the first projection system space 62 and thesecond projection system space 63. The orifice member 52 may be of anyshape if it is a member which can produce a pressure difference betweenthe first projection system space 62 and the second projection systemspace 63. It may simply be a small opening, or as shown in FIG. 1, maybe a cylindrical elongate member (the height of the cylinder maypreferably be three or more times as great as the diameter of thethinnest portion of the cylinder, and may more preferably be five ormore times).

Such an orifice member 52 as does not intercept exposure light aspreviously described is installed between the first projection systemspace 62 and the second projection system space 63. The first projectionsystem space 62 can be kept at predetermined pressure by exhaust devices32 and 33 such as turbo-molecular pumps connected thereto and a pressuresensor S1, and the second projection system space 63 can be kept atpredetermined pressure by turbo-molecular pumps 34 and 35 and a pressuresensor S2. Further, the exposure apparatus has a valve (inert gassupplying device) V1 which supplies an inert gas such as helium into thesecond projection system space 63, and can control the mass flow rate ofgas.

A shield member 51 having an opening portion for passing the exposurelight and alignment light therethrough is disposed between a reticlestage space 61 and the first projection system space 62. Here, thedistance between the shield member 51 and the reticle is set to be 1 mmor less. By the configuration, a pressure difference can also beproduced between the reticle stage space 61 and the first projectionsystem space 62.

This reticle stage space 61 can be kept at predetermined pressure by anexhaust device 31 such as a turbo-molecular pump connected thereto and apressure sensor S3. Also, the first projection system space 62 can bekept at predetermined pressure by the exhaust devices 32 and 33 such asthe turbo-molecular pumps connected thereto and the pressure sensor S1.If as described above, an operative exhaust system is configured betweenthe reticle stage space 61 and the first projection system space 62 andthe pressure in the first projection system space 62 is made higher thanthat in the reticle stage space 61, out gas produced from the reticlestage space 61 can be deterred from entering the first projection systemspace 62.

Next, between the second projection system space 63 and a wafer stagespace 64, a wafer stage space opening portion 53, which does notintercept the exposure light, is disposed. Also, the wafer stage space64 is kept at predetermined pressure by a turbo-molecular pump 36connected thereto and a pressure sensor S4.

The out gas produced from the mechanism portions or the like of thereticle stage 13 and the wafer stage 23 is exhausted by the use of adifferential exhaust system, whereby it can be deterred from adhering tothe mirror, etc. of the aforedescribed projection optical system.

However, The deterring effect of the out gas produced from resist duringexposure by differential exhaust can be little expected because thewafer stage space opening portion 53 and the wafer are proximate to eachother. So, helium is supplied to the second projection system space 63by the utilization of the valve (inert gas supplying means) V1. Thesupplied helium fills the second projection system space 63, and isejected from the orifice member 52 to the first projection system space62, and from the wafer stage space opening portion 53 to the wafer stagespace 64. At this time, the system is configured such that the pressurein the second projection system space 63 may be kept at the order of 1to 10 Pa (or 0.1 to 100 Pa) and pressure of the first projection systemspace 62 and the wafer stage space 64 may be kept equal to or less thanthat in the second projection system space 63. By thus making thepressure in the wafer stage space 64 (and the first projection systemspace 62) adjacent to the second projection system space low relative tothe pressure in the second projection system space 63, it becomespossible to effectively deter the out gas produced form the resist.

Further, by configuring such that the conductance of the orifice member52 is lower than the conductance of the wafer stage space openingportion 53, it is possible to further deter the out gas produced fromthe resist from reaching the mirror of the projection optical system.

In order to confirm the above-described deterring effect by the supplyof the inert gas, thermohydrodynamic simulation was carried out. Theresult is shown in FIG. 2.

The axis of abscissas in FIG. 2 indicates the amount of helium supply(He mass flow rate), and the axis of ordinates indicates the partialpressure of the out gas produced from the resist in the secondprojection system space 63. The mark ◯ indicates the result of the casewhere helium was supplied, the mark A indicates the result of the casewhere helium was supplied and the conductance of the orifice member 52was set to a lower value than that of the wafer stage space openingportion 53, and the mark □ indicates the result of the case where theconductance of the orifice member 52 was set to an infinitely low value.Also, the partial pressure of the out gas when helium was not suppliedwas about 1×10⁻3 Pa.

From these results, it will be seen that by supplying helium to thesecond projection system space, it is possible to pervert the out gasproduced from the resist from entering the second projection systemspace and further, by setting the conductance of the orifice member 52to a lower value than that of the wafer stage space opening portion 53,it is possible to more enhance the deterring effect.

Also, by providing the orifice member 52, it is possible to suppress theoutflow rate of helium to the first projection system space 62 andtherefore, it is possible to suppress the amount of consumption ofexpensive helium. Further, by providing this orifice member 52, itbecomes possible to lower the partial pressure of helium in the firstprojection system space 62 and therefore, the transmittance of the EUVlight, which is also absorbed by helium, can be kept high, and animprovement in throughput can be achieved.

Also, it is preferable that the exhaust speed of the turbo-molecularpump or the like mounted in the second projection system space 63 be setto a lower value than the exhaust speeds of the first projection systemspace 62 and the wafer stage space 64 in order to keep the pressure inthe second projection system space 63 higher than the pressure in thefirst projection system space 62 and the wafer stage space 64.

Also, of the helium supplied to the second projection system space 63,the flow out rate into the wafer stage space 64 through the wafer stagespace opening portion is made greater than the flow out rate into thereticle stage space 61 through the orifice member 51, whereby it iseffectively possible to prevent the out gas produced from the resistfrom entering the second projection system space 63.

Here, among the reticle stage space, the first projection system space,the second projection system space and the wafer stage space, it ispreferable that the pressure in the second projection system space,which is nearest to the wafer stage space, be made highest. Describingin more detail, it is preferable that the pressure in the firstprojection system space be the second highest, and it is desirable thatthe pressure in the reticle stage space be the third highest and thepressure in the wafer stage space be lowest. Of course, this is notrestrictive, but the pressure in the first projection system space maybe made highest. It is desirable at least that the pressure in the firstprojection system space and the second projection system space arehigher than the pressure in the reticle stage space and the wafer stagespace.

Also, in this first embodiment, the space containing therein the opticalelement, which the projection optical system has, is divided into twospaces, i.e., the first projection system space and the secondprojection system space, whereas this is not restrictive, but theaforementioned space may be divided into three or more spaces. Even inthat case, it is desirable that the pressure in the space nearest to thewafer stage space be made highest, and further, it is desirable that thepressure in all of the spaces in the projection optical system exceedsthe pressure in the reticle stage space and the wafer stage space.

Also, it is desirable that the pressure in all the spaces on the opticalpath of the EUV light, including the reticle stage space, the firstprojection system space, the second projection system space and thewafer stage space be 100 Pa or less, and preferably 10 Pa or less.

(Second Embodiment)

FIG. 2 shows the configuration of the second embodiment.

The projection system space disposed between the reticle stage space 61and the wafer stage space 64 has an opening portion 54 and an orificemember 52, and is composed of a first projection system space 62, asecond projection system space 63 and a third projection system space65.

The previous embodiment is a case where an inert gas is supplied only tothe second projection system space 63, however in the presentembodiment, piping branches off from a valve V3 for supplying the inertgas, and a valve V1 for supplying the inert gas to the second projectionsystem space 63 and a valve 2 for supplying the inert gas to the firstprojection system space 62 are configured. The valves V1, V2 and V3 cancontrol the gas supply rate in conformity with the pressure in thespaces to which the inert gas is to be supplied.

The pressure in the first projection system space 62 is kept atpredetermined pressure by a turbo-molecular pump 32 connected theretoand a pressure sensor S1. Also, the first projection system space 62configures a multi-stage differential exhaust system by turbo-molecularpumps 37 and 38 in a portion on which EUV light is incident from an EUVlight source, not shown.

The pressure in the third projection system space 65 is kept atpredetermined pressure by turbo-molecular pumps 33, 34, 39 and 40connected thereto and a pressure sensor S5.

The pressure in the second projection system space 63 is also kept atpredetermined pressure by turbo-molecular pumps 35 and 41 connectedthereto and a pressure sensor S2.

In the first embodiment, helium is supplied to the second projectionsystem space 63 by the utilization of the valve V1, whereby the out gasproduced from the resist during exposure can be effectively preventedfrom entering the second projection system space 63. Also, for the outgas produced from the reticle stage space 61, a differential exhaustsystem is configured.

However, if there is at least one space between the space (the secondprojection system space 63) supplied with helium and the space (thefirst projection system space 62) adjacent to the reticle stage space asin a case of this second embodiment, it is also conceivable to configurea multi-stage differential exhaust system in order to deter the out gasproduced from the reticle stage space 61 from entering the firstprojection system space 62, however, it may contain spatial difficulty.

So, helium is supplied to the first projection system space 62 and thesecond projection system space 63 by the use of the valves V1, V2 andV3. That is, the configuration is made such that helium is supplied tothe space adjacent to the reticle stage space and to the space adjacentto the wafer stage space. The helium supplied to the second projectionsystem space 63 flows as described in the first embodiment, and thehelium supplied to the first projection system space 62 fills the firstprojection system space, and flows into the third projection systemspace 65 through the opening portion 54, and further flows into thereticle stage space 61 through the reticle stage space opening portion51.

At this time, the pressure in the first projection system space 62 iskept at about 1 to 10 Pa, and the pressure in the third projectionsystem space 65 and the reticle stage space 61 is kept below it, wherebyit is possible to deter the out gas produced from the reticle stagespace from entering the first projection system space 62.

Further, when helium is supplied into the first projection system space62, the conductance of the opening portion 54 is set to a lower valvethan that of the reticle stage space opening portion 51, whereby the outgas produced from the reticle stage space can be better deterred fromentering the first projection system space 62.

Also, by providing the stop portion 52 and the opening portion 54, it ispossible to lower the partial pressure of the helium in the projectionsystem space 65, and it is possible to keep the transmittance ofexposure light high and it is also possible to suppress the amount ofconsumption of helium supplied.

Also, it is desirable that the exhaust speed of the turbo-molecularpumps, etc., mounted in the first projection system space 62 and thesecond projection system space 63 be set to a lower level than theexhaust speeds of the third projection system space 65, the wafer stagespace 64 and the reticle stage space 61 in order to keep the pressure inthe first projection system space 62 and the second projection systemspace 63 higher than the pressure in the third projection system space65, the wafer stage space 64 and the reticle stage space 61.

Also, of the helium supplied to the first projection system space 62,the flow out rate into the wafer stage space is made greater than theflow out rate from the reticle stage space opening portion 51, or ismade greater than the flow out rate from the orifice member 52 into thethird projection system space, whereby the out gas produced from theresist can be effectively deterred from entering the second projectionsystem space 63.

While the first and second embodiments have been described above, thepresent invention is not restricted thereto.

In the exposing apparatus in the present embodiment, the pressure in thewafer stage space is made lower than the pressure in the space (thesecond projection system space) of the projection optical system whichis adjacent to the wafer stage space.

Further, the configuration is made such that the inert gas flow out ratefrom the second projection system space into the wafer stage spacebecomes greater than the inert gas flow out rate from the secondprojection system space into the space (in the first embodiment, thefirst projection system space, and in the second embodiment, the thirdprojection system space) adjacent to the second projection system spaceon the reticle side.

Furthermore, the configuration is made such that among the reticle stagespace, the wafer stage space and at least one space (preferably aplurality of spaces) containing the optical element of the projectionoptical system therein, the pressure in the space containing the opticalelement of the projection optical system and adjacent to the wafer stagespace is made highest.

Still furthermore, it is preferable that the configuration be made suchthat the volume of the space (in the first and second embodiments, thesecond projection system space) adjacent to the wafer stage space isless than a half, preferably one-third or less, of the volume of theentire space containing the optical element of the projection opticalsystem therein.

Also, while in the above-described embodiments, helium is supplied, thisis not restrictive, however, and other inert gas such as nitrogen orargon may be used. Also, while in the above-described embodiments, avalve is provided so that the helium mass flow rate may be adjustable,the configuration may be made such that helium is always supplied at aconstant flow rate.

Also, it is desirable that among the wafer stage space, the reticlestage space, the space (the second projection system space in the firstand second embodiments) adjacent to the wafer stage, and the stage (thefirst projection system space in the first and second embodiments)adjacent to the reticle stage, the space adjacent to the wafer stage belowest in the exhaust speed at which the gas in the respective space isexhausted, and that the space adjacent to the reticle stage be secondlowest in this exhaust speed. The lowest and the second lowest may beconverse.

Also, in the second embodiment, the third projection system space is notlimited to one space, but may be constituted by a plurality of spacescapable of being communicated with one another.

Also, when according to such embodiments as described above, the inertgas is supplied into the projection optical system space to therebydeter the out gas from the wafer stage space from entering theprojection optical system space, it is possible to dispose an orificemember for generating differential pressure in the projection opticalsystem space to thereby deter the out gas more effectively.

Also, the pressure rise in the projection optical system space by thesupply of the inert gas can be partly restricted and therefore, it ispossible to suppress the lowering of the transmittance of the EUV lightand keep a high throughput.

Also, the above-described first and second embodiments may bearbitrarily combined together within a scope free of contradiction.

(Third Embodiment)

A third embodiment, which is a device manufacturing method utilizing theabove-described exposing apparatus, is described with reference to FIGS.5 and 6.

FIG. 5 is a flow chart for illustrating the manufacture of a device (asemiconductor chip such as IC or LSI, an LCD, a CCD or the like). In thepresent embodiment, the manufacture of a semiconductor chip will bedescribed as an example. In step 1 (circuit design), the circuit designof a device is done. In step 2 (mask making), a mask formed with adesigned circuit pattern is fabricated. In step 3 (wafer fabrication), awafer is fabricated from material such as silicon. Step 4 (waferprocessing) is called an upstream process, and forms an actual circuiton the wafer by lithography technique by the use of the mask and thewafer. Step 5 (packaging) is called a downstream process, and is thestep of making a semiconductor chip by the use of the wafer prepared inthe step 4, and includes such steps as an assembly step (dicing andbonding), a packaging step (chip enveloping), etc. In step 6 (testing),such tests as the operation confirming test and durability tests of thesemiconductor device prepared in the step 5, are carried out. Thesemiconductor device is completed via such steps, and it is shipped(step 7).

FIG. 6 is a detailed flow chart of the wafer processing of the step 4.In step 11 (oxidation), the surface of the wafer is oxidated. In step 12(CVD), insulating film is formed on the surface of the wafer. In step 13(electrode formation), an electrode is formed on the wafer by vapordeposition or the like. In step 14 (ion implantation), ions areimplanted into the wafer. In step 15 (resist processing), a sensitizeris applied to the wafer. In step 16 (exposure), the wafer is exposed tothe circuit pattern of the mask by the above-described exposingapparatus. In step 17 (developing), the exposed wafer is developed. Instep 18 (etching), the other portion than the developed resist image isshaved off. In step 19 (resist stripping), the resist, which has becomeunnecessary after etching, is removed. These steps are repetitivelyexecuted, whereby a multiple circuit pattern is formed on the wafer.According to the device manufacturing method of the present embodiment,a device with higher quality than heretofore can be manufactured. Thus,the device manufacturing method using the exposing apparatus, and thedevice as a result thereof also constitute a side of the presentinvention.

While the preferred embodiments of the present invention have beendescribed above, the present invention permits the first, second andthird embodiments to be arbitrarily combined together.

The mass flow rate of out gas entering the projection optical systemfrom the wafer stage space can be decreased and therefore, the opticalelement, which the projection optical system has, becomes difficult tobe contaminated. As the result, the frequency of the maintenance of theexposing apparatus can be reduced and therefore, the throughput of theexposing apparatus can be improved.

(Fourth Embodiment)

An EUV exposing apparatus as a side of the present invention willhereinafter be described with reference to FIG. 7. The configurationaldifferences between this EUV exposing apparatus and the aforedescribedembodiments will first be described. FIG. 7 is a block diagram showingthe configuration of the exposing apparatus. In the previousembodiments, description has been made of a method for preventingcontamination present in the reticle stage space and the wafer stagespace from entering the projection optical system space. In the presentembodiment, description will be made of a method for suppressing theadherence of particles present in the stage spaces and the projectionoptical system space to the surface of the reticle and the surface ofthe wafer.

Cooling members CP1 and CP2 are provided near a reticle stage spaceopening portion 51 and a wafer stage space opening portion 53,respectively, shown in FIG. 7. CP1 and CP2 are members having a coolingmechanism connected thereto, and are disposed at locations opposed tothe surface of the reticle or the surface of the wafer. Each connectedmember has a pipe for cooling wafer or a Peltier element or the likeconnected thereto as a cooling mechanism, not shown, and is cooled at aconstant temperature. The areas of the surface of the wafer and thesurface of the reticle, to which exposure light is applied, rise intemperature by the heat of the exposure light, and the temperaturebecomes higher than that of the cooling members CP1 and CP2. Therefore,during exposure, a temperature difference occurs between the coolingmembers CP1, CP2 and the surface of the reticle, the surface of thewafer. Also, usually the reticle and the wafer are controlled so thatthe temperature thereof may become constant and therefore, it is alsopossible to control the temperature of the surfaces of the reticle andthe wafer by the cooling members CP1 and CP2. Also, the reticle and thewafer may be individually temperature-controlled, and relative to theset temperature thereof, the temperature of the cooling members CP1 andCP2 may be set to a low temperature.

Also, an inert gas such as He, which is high in transmittance of EUVlight, or hydrogen is supplied through valves V1 and V2. To obtain theeffect of thermophoresis for suppressing particles, it is preferable toset the pressure in a reticle stage space 61 and a wafer stage space 64to at least 5 Pa or greater.

By so setting, it is possible to suppress the adherence of the particlesto the surface of the reticle and the surface of the wafer bythermophoresis.

While in the present embodiment, there has been shown a configurationwhich obtains the particle suppressing effect for both of the wafer andthe reticle, it is possible to carry out this for at least one of themto thereby obtain an improvement in productivity.

According to the present invention, there can be provided an exposingapparatus which simply achieves improvements in productivity such as theyield of the manufacture of a device and the reliability of the device.

The practice modes of the present invention will hereinafter beenumerated.

(Practice Mode 1)

An exposing apparatus having a projection optical system having aplurality of optical elements and for directing light from a reticle toa member to be exposed, a wafer stage on which the member to be exposedis placed, and a wafer stage space surrounding the wafer stage, theexposing apparatus having:

-   -   a wafer side projection system space containing at least one of        the plurality of optical elements therein, adjacent to the wafer        stage space, and communicating with the wafer stage space        through a wafer stage opening;    -   wherein pressure in the wafer side projection system space is        higher than pressure in the wafer stage space.        (Practice Mode 2)

An exposing apparatus according to Practice Mode 1, further having waferside projection system space exhaust means for exhausting gas in thewafer side projection system space, and wafer stage space exhaust meansfor exhausting gas in the wafer stage space, and wherein an exhaustspeed by the wafer side projection system space exhaust means is lowerthan an exhaust speed by the wafer stage space exhaust means.

(Practice Mode 3)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a wafer stage on which the member to be exposedis placed, and a wafer stage space surrounding the wafer stage, theexposing apparatus having:

-   -   a wafer side projection system space containing at least one of        the plurality of optical elements therein, adjacent to the wafer        stage space, and communicating with the wafer stage space        through a wafer stage opening, wafer side projection system        space exhaust means for exhausting gas in the wafer side        projection system space, and wafer stage space exhaust means for        exhausting gas in the wafer stage space;    -   wherein an exhaust speed by the wafer side projection system        space exhaust means is lower than an exhaust speed by the wafer        stage space exhaust means.        (Practice Mode 4)

An exposing apparatus according to any one of Practice Modes 1 to 3,further having an intermediate projection system space containinganother one of the plurality of optical elements therein, adjacent tothe wafer side projection system space, and communicating with the waferside projection system space through a wafer side opening, and whereinpressure in the wafer side projection system space is higher thanpressure in the intermediate projection system space.

(Practice Mode 5)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a wafer stage on which the member to be exposedis placed, and a wafer stage space surrounding the wafer stage, theexposing apparatus having:

-   -   a wafer side projection system space containing at least one of        the plurality of optical elements therein, adjacent to the wafer        stage space, and communicating with the wafer stage space        through a wafer stage opening; and    -   an intermediate projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        wafer side projection system space, and communicating with the        wafer side projection system space through a wafer side opening;    -   wherein a gas flow rate from the wafer side projection system        space into the wafer stage space is greater than a gas flow rate        from the wafer side projection system space into the        intermediate projection system space.        (Practice Mode 6)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a wafer stage on which the member to be exposedis place, and a wafer stage space surrounding the wafer stage, theexposing apparatus having:

-   -   a wafer side projection system space containing at least one of        the plurality of optical elements therein, adjacent to the wafer        stage space, and communicating with the wafer stage space        through a wafer stage opening; and    -   an intermediate projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        wafer side projection system space, and communicating with the        wafer side projection system space through a wafer side opening;    -   wherein the conductance of a communicating portion between the        wafer side projection system space and the wafer stage space is        greater than the conductance of a communicating portion between        the wafer side projection system space and the intermediate        projection system space.        (Practice Mode 7)

An exposing apparatus according to Practice Mode 6, wherein a gas flowrate from the wafer side projection system space into the wafer stagespace is greater than a gas flow rate from the wafer side projectionsystem space into the intermediate projection system space.

(Practice Mode 8)

An exposing apparatus according to any one of Practice Modes 5 to 8,wherein pressure in the wafer side projection system space is higherthan pressure in the wafer stage space.

(Practice Mode 9)

An exposing apparatus according to any one of Practice Modes 4 to 8,further having wafer side projection system space exhaust means forexhausting gas in the wafer side projection system space, wafer stagespace exhaust means for exhausting gas in the wafer stage space, andintermediate projection system space exhaust means for exhausting gas inthe intermediate projection system space, and wherein an exhaust speedby the wafer side projection system space exhaust means is lower than anexhaust speed by the wafer stage space exhaust means and an exhaustspeed by the intermediate projection system space exhaust means.

(Practice Mode 10)

An exposing apparatus according to Practice Mode 9, wherein the exhaustspeed by the wafer stage space exhaust means is made higher than theexhaust speed by the intermediate projection system space exhaust means.

(Practice Mode 11)

An exposing apparatus according to any one of Practice Modes 4 to 10,further having a reticle stage on which the reticle is placed, a reticlestage space surrounding the reticle stage, and a reticle side projectionsystem space containing at least one of the plurality of opticalelements therein, adjacent to the reticle stage space, and communicatingwith the reticle stage space through a reticle stage opening, andwherein the intermediate projection system space contains at least oneof the plurality of optical elements, is adjacent to the reticle sideprojection system space, and communicates with the reticle sideprojection system space through a reticle side opening, and pressure inthe reticle side projection system space is higher than pressure in thereticle stage space and pressure in the intermediate projection systemspace.

(Practice Mode 12)

An exposing apparatus according to any one of Practice Modes 4 to 11,further having a reticle stage on which the member to be exposed isplaced, a reticle stage space surrounding the reticle stage, and areticle side projection system space containing at least one of theplurality of optical elements, adjacent to the reticle stage space, andcommunicating with the reticle stage space through a reticle stageopening, and wherein the intermediate projection system space containsat least one of the plurality of optical elements therein, is adjacentto the reticle side projection system space, and communicates with thereticle side projection system space through a reticle side opening, anda gas flow rate from the reticle side projection system space into thereticle stage space is greater than the gas flow rate from the reticleside projection system space into the intermediate projection systemspace.

(Practice Mode 13)

An exposing apparatus according to any one of Practice Modes 4 to 12,further having a reticle stage on which the member to be exposed isplaced, a reticle stage space surrounding the reticle stage, and areticle side projection system space containing at least one of theplurality of optical elements therein, adjacent to the reticle stagespace, and communicating with the reticle stage space through a reticlestage opening, and wherein the intermediate projection system spacecontains at least one of the plurality of optical elements therein, isadjacent to the reticle side projection system space, and communicateswith the reticle side projection system space through a reticle sideopening, and the conductance of a communicating portion between thereticle side projection system space and the reticle stage space isgreater than the conductance of a communicating portion between thereticle side projection system space and the intermediate projectionsystem space.

(Practice Mode 14)

An exposing apparatus according to any one of Practice Modes 11 to 13,further having reticle stage space exhaust means for exhausting gas inthe reticle stage space, reticle side projection system space exhaustmeans for exhausting gas in the reticle side projection system space,intermediate projection system space exhaust means for exhausting gas inthe intermediate projection system space, wafer side projection systemspace exhaust means for exhausting gas in the wafer side projectionsystem space, and wafer stage space exhaust means for exhausting gas inthe wafer stage space, and wherein among the reticle stage space exhaustmeans, the reticle side projection system space exhaust means, theintermediate projection system space exhaust means, the wafer sideprojection system space exhaust means and the wafer stage space exhaustmeans, the exhaust speed of the wafer side projection system spaceexhaust means is lowest.

(Practice Mode 15)

An exposing apparatus according to any one of Practice Modes 11 to 14,further having reticle stage space exhaust means for exhausting gas inthe reticle stage space, reticle side projection system space exhaustmeans for exhausting gas in the reticle side projection system space,intermediate projection system space exhaust means for exhausting gas inthe intermediate projection system space, wafer side projection systemspace exhaust means for exhausting gas in the wafer side projectionsystem space, and wafer stage space exhaust means for exhausting gas inthe wafer stage space, and wherein the exhaust speed of the wafer sideprojection system space exhaust means is lower than the exhaust speedsof the intermediate projection system space exhaust means and the waferstage space exhaust means, and the exhaust speed of the reticle sideprojection system space exhaust means is lower than the exhaust speed ofthe reticle stage space exhaust means and the exhaust speed of theintermediate projection system space exhaust means.

(Practice Mode 16)

An exposing apparatus according to any one of Practice Modes 11 to 15,wherein pressure in the wafer stage space is lower than pressure in thereticle stage space.

(Practice Mode 17)

An exposing apparatus according to any one of Practice Modes 1 to 16,further having an orifice member disposed in a communicating portionbetween the wafer stage space and the wafer side projection systemspace.

(Practice Mode 18)

An exposing apparatus according to any one of Practice Modes 1 to 17,further having gas-feeding means for supplying inert gas to the waferside projection system space.

(Practice Mode 19)

An exposing apparatus according to Practice Mode 18, wherein the inertgas is one of helium and argon.

(Practice Mode 20)

An exposing apparatus according to Practice Mode 18 or 19, furtherhaving means for measuring the flow rate of the inert gas supplied bythe gas supplying means, and wherein the frow rate of inert gas iscontrolled in conformity with the pressure in the wafer side projectionsystem space.

(Practice Mode 21)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a reticle stage on which the reticle is placed,and a reticle stage space surrounding the reticle stage, the exposingapparatus having:

-   -   a reticle side projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle stage space, and communicating with the reticle stage        space through a reticle stage opening;    -   wherein pressure in the reticle side projection system space is        higher than pressure in the reticle stage space.        (Practice Mode 22)

An exposing apparatus according to Practice Mode 21, further havingreticle side projection system space exhaust means for exhausting gas inthe reticle side projection system space, and reticle stage spaceexhaust means for exhausting gas in the reticle stage space, and whereinan exhaust speed by the reticle side projection system space exhaustmeans is lower than an exhaust speed by the reticle stage space exhaustmeans.

(Practice Mode 23)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a reticle stage on which the reticle is placed,and a reticle stage space surrounding the reticle stage, the exposingapparatus having:

-   -   a reticle side projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle stage space, and communicating with the reticle stage        space through a reticle stage opening;    -   wherein an exhaust speed by reticle side projection system space        exhaust means is lower than an exhaust speed by reticle stage        space exhaust means.        (Practice Mode 24)

An exposing apparatus according to any one of Practice Modes 21 to 23,further having an intermediate projection system space containing atleast one of the plurality of optical elements therein, adjacent to thereticle side projection system space, and communicating with the reticleside projection system space through a reticle side opening, and whereinpressure in the reticle side projection system space is higher thanpressure in the intermediate projection system space.

(Practice Mode 25)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a reticle stage on which the member to beexposed is placed, and a reticle stage space surrounding the reticlestage, the exposing apparatus having:

-   -   a reticle side projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle stage space, and communicating with the reticle stage        space through a reticle stage opening; and    -   an intermediate projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle side projection system space, and communicating with the        reticle side projection system space through a reticle side        opening;    -   wherein a gas flow rate from the reticle side projection system        space into the reticle stage space is greater than a gas flow        rate from the reticle side projection system space into the        intermediate projection system space.        (Practice Mode 26)

An exposing apparatus having a projection optical system having aplurality of optical elements, and for directing light from a reticle toa member to be exposed, a reticle stage on which the member to beexposed is placed, and a reticle stage space surrounding the reticlestage, the exposing apparatus having:

-   -   a reticle side projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle stage space, and communicating with the reticle stage        space through a reticle stage opening; and    -   an intermediate projection system space containing at least one        of the plurality of optical elements therein, adjacent to the        reticle side projection system space, and communicating with the        reticle side projection system space through a reticle side        opening;    -   wherein the conductance of a communicating portion between the        reticle side projection system space and the reticle stage space        is greater than the conductance of a communicating portion        between the reticle side projection system space and the        intermediate projection system space.        (Practice Mode 27)

An exposing apparatus according to any one of Practice Modes 4 to 6 and24 to 26, wherein the intermediate projection system space includes aplurality of spaces capable of communicating with one another.

(Practice Mode 28)

An exposing apparatus according to any one of Practice Modes 1 to 27,wherein all of the plurality of optical elements are reflecting opticalelements.

(Practice Mode 29)

An exposing apparatus according to any one of Practice Modes 1 to 28,wherein the wavelength of the light used in the exposing apparatus isbetween 0.1 nm to 30 nm.

(Practice Mode 30)

A method of device manufacturing having a step of exposing the member tobe exposed by the use of an exposing apparatus according to any one ofPractice Modes 1 to 29, and a step of developing the exposed member tobe exposed.

The present invention is not restricted to the above embodiments andvarious changes and modifications can be made within the spirit andscope of the present invention. Therefore, to apprise the public of thescope of the present invention, the following claims are made.

This application claims priority from Japanese Patent Application No.2003-337562, entitled “Manufacture method of exposure apparatus anddevice” and filed on Sep. 29, 2003, and Japanese Patent Application No.2004-242229, entitled “Manufacture method of exposure apparatus anddevice” and filed on Aug. 23, 2004, the entire contents of which areincorporated herein by reference.

1. An exposure apparatus comprising: a projection optical system whichhas a plurality of optical elements, and directs light from an originalto an object to be exposed; a first stage which holds the object to beexposed; a first vacuum chamber which contains said first stage; and asecond vacuum chamber which is adjacent to said first vacuum chamber,contains a part of said plurality of optical elements, and communicateswith said first vacuum chamber through a first opening; wherein pressurein said second vacuum chamber is higher than pressure in said firstvacuum chamber.
 2. An apparatus according to claim 1, furthercomprising: a first exhaust unit which exhausts gas in said first vacuumchamber; and a second exhaust unit which exhausts gas in said secondvacuum chamber, wherein an exhaust rate by said second exhaust unit islower than an exhaust rate by said first exhaust unit.
 3. An apparatusaccording to claim 1, further comprising: a third vacuum chamber whichis adjacent to said second vacuum chamber, contains another one of saidplurality of optical elements, and communicates with said second vacuumchamber through a second opening, wherein the pressure in said secondvacuum chamber is higher than pressure in said third vacuum chamber. 4.An apparatus according to claim 3, wherein a gas flow rate from saidsecond vacuum chamber into said first vacuum chamber is greater than agas flow rate from said second vacuum chamber into said third vacuumchamber.
 5. An apparatus according to claim 4, wherein conductance of acommunicating portion between said second vacuum chamber and said firstvacuum chamber is greater than conductance of a communicating portionbetween said second vacuum chamber and said third vacuum chamber.
 6. Anapparatus according to claim 3, further comprising: a first exhaust unitwhich exhausts gas in said first vacuum chamber; a second exhaust unitwhich exhausts gas in said second vacuum chamber; and a third exhaustunit for exhausting gas in said third vacuum chamber, wherein an exhaustrate by said second exhaust unit is lower than an exhaust rate by saidfirst exhaust unit and an exhaust rate by said third exhaust unit.
 7. Anapparatus according to claim 6, wherein the exhaust rate by said firstexhaust unit is higher than the exhaust rate by said third exhaust unit.8. An apparatus according to claim 3, further comprising: a second stagewhich holds the original; a fourth vacuum chamber containing said secondstage therein; and a fifth vacuum chamber which is adjacent to saidfourth vacuum chamber, contains a part of said plurality of opticalelements, and communicates with said fourth vacuum chamber through athird opening, wherein said third vacuum chamber is adjacent to saidfifth vacuum chamber, and communicates with said fifth vacuum chamberthrough a fourth opening, and pressure in said fifth vacuum chamber ishigher than pressure in said fourth vacuum chamber and pressure in saidthird vacuum chamber.
 9. An apparatus according to claim 8, wherein agas flow rate from said fifth vacuum chamber into said fourth vacuumchamber is greater than a gas flow rate from said fifth vacuum chamberinto said third vacuum chamber.
 10. An apparatus according to claim 9,wherein conductance of a communicating portion between said fifth vacuumchamber and said fourth vacuum chamber is greater than conductance of acommunicating portion between said fifth vacuum chamber and said thirdvacuum chamber.
 11. An apparatus according to claim 8, furthercomprising: a first exhaust unit which exhausts gas in said first vacuumchamber; a second exhaust unit which exhausts gas in said second vacuumchamber; a third exhaust unit which exhausts gas in said third vacuumchamber; a fourth exhaust unit which exhausts gas in said fourth vacuumchamber; and a fifth exhaust unit which exhausts gas in said fifthvacuum chamber, wherein an exhaust rate by said second exhaust unit islowest among exhaust rates of said first to fifth exhaust units.
 12. Anapparatus according to claim 8, further comprising: a first exhaust unitwhich exhausts gas in said first vacuum chamber; a second exhaust unitwhich exhausts gas in said second vacuum chamber; a third exhaust unitwhich exhausts gas in said third vacuum chamber; a fourth exhaust unitwhich exhausts gas in said fourth vacuum chamber; and a fifth exhaustunit which exhausts gas in said fifth vacuum chamber, wherein an exhaustrate by said second exhaust unit is lower than an exhaust rate by saidfirst exhaust unit and an exhaust rate by said third exhaust unit, andan exhaust rate by said fifth exhaust unit is lower than the exhaustrate by said third exhaust unit and an exhaust rate by said fourthexhaust unit.
 13. An apparatus according to claim 8, wherein pressure insaid first vacuum chamber is lower than pressure in said fourth vacuumchamber.
 14. An apparatus according to claim 3, further comprising amember which defines the second opening.
 15. An apparatus according toclaim 1, further comprising a gas supply unit which supplies inert gasinto said second vacuum chamber.
 16. An apparatus according to claim 15,wherein the inert gas is one of helium, nitrogen and argon.
 17. Anapparatus according to claim 15, wherein a feed rate of the inert gas bysaid gas supply unit is controlled in accordance with pressure in saidsecond vacuum chamber.
 18. An exposure apparatus comprising: aprojection optical system which has a plurality of optical elements, anddirects light from an original to an object to be exposed; a first stagewhich holds the original; a first vacuum chamber which contains saidfirst stage; and a second vacuum chamber which is adjacent to said firstvacuum chamber, contains a part of said plurality of optical elements,and communicates with said first vacuum chamber through a first opening,wherein pressure in said second vacuum chamber is higher than pressurein said first vacuum chamber.
 19. An apparatus according to claim 3,wherein said third vacuum chamber includes a plurality of vacuumchambers communicating with one another.
 20. An apparatus according toclaim 1, wherein all of said plurality of optical elements arereflecting optical elements.
 21. An apparatus according to claim 1,wherein a wavelength of the light is between 0.1 nm to 30 nm.
 22. Adevice manufacturing method comprising steps of: exposing an object to apattern using an exposure apparatus as recited in claim 1; anddeveloping the exposed object.
 23. An apparatus according to claim 1,further comprising: a member arranged in said first vacuum chamber, andcooled by a cooling mechanism.
 24. An apparatus according to claim 23,wherein pressure in said first vacuum chamber is not less than 5 Pa. 25.An apparatus according to claim 2, wherein all of said plurality ofoptical elements are reflecting optical elements.
 26. An apparatusaccording to claim 3, wherein all of said plurality of optical elementsare reflecting optical elements.
 27. An apparatus according to claim 4,wherein all of said plurality of optical elements are reflecting opticalelements.
 28. An apparatus according to claim 5, wherein all of saidplurality of optical elements are reflecting optical elements.
 29. Anapparatus according to claim 6, wherein all of said plurality of opticalelements are reflecting optical elements.
 30. An apparatus according toclaim 7, wherein all of said plurality of optical elements arereflecting optical elements.
 31. An apparatus according to claim 8,wherein all of said plurality of optical elements are reflecting opticalelements.
 32. An apparatus according to claim 9, wherein all of saidplurality of optical elements are reflecting optical elements.
 33. Anapparatus according to claim 10, wherein all of said plurality ofoptical elements are reflecting optical elements.
 34. An apparatusaccording to claim 11, wherein all of said plurality of optical elementsare reflecting optical elements.
 35. An apparatus according to claim 12,wherein all of said plurality of optical elements are reflecting opticalelements.
 36. An apparatus according to claim 13, wherein all of saidplurality of optical elements are reflecting optical elements.
 37. Anapparatus according to claim 14, wherein all of said plurality ofoptical elements are reflecting optical elements.
 38. An apparatusaccording to claim 15, wherein all of said plurality of optical elementsare reflecting optical elements.
 39. An apparatus according to claim 16,wherein all of said plurality of optical elements are reflecting opticalelements.
 40. An apparatus according to claim 17, wherein all of saidplurality of optical elements are reflecting optical elements.
 41. Anapparatus according to claim 18, wherein all of said plurality ofoptical elements are reflecting optical elements.
 42. An apparatusaccording to claim 2, wherein a wavelength of the light is between 0.1nm to 30 nm.
 43. An apparatus according to claim 3, wherein a wavelengthof the light is between 0.1 nm to 30 nm.
 44. An apparatus according toclaim 4, wherein a wavelength of the light is between 0.1 nm to 30 nm.45. An apparatus according to claim 5, wherein a wavelength of the lightis between 0.1 nm to 30 nm.
 46. An apparatus according to claim 6,wherein a wavelength of the light is between 0.1 nm to 30 nm.
 47. Anapparatus according to claim 7, wherein a wavelength of the light isbetween 0.1 mm to 30 nm.
 48. An apparatus according to claim 8, whereina wavelength of the light is between 0.1 nm to 30 nm.
 49. An apparatusaccording to claim 9, wherein a wavelength of the light is between 0.1nm to 30 nm.
 50. An apparatus according to claim 10, wherein awavelength of the light is between 0.1 nm to 30 nm.
 51. An apparatusaccording to claim 11, wherein a wavelength of the light is between 0.1nm to 30 nm.
 52. An apparatus according to claim 12, wherein awavelength of the light is between 0.1 nm to 30 mm.
 53. An apparatusaccording to claim 13, wherein a wavelength of the light is between 0.1nm to 30 nm.
 54. An apparatus according to claim 14, wherein awavelength of the light is between 0.1 nm to 30 nm.
 55. An apparatusaccording to claim 15, wherein a wavelength of the light is between 0.1nm to 30 nm.
 56. An apparatus according to claim 16, wherein awavelength of the light is between 0.1 mm to 30 nm.
 57. An apparatusaccording to claim 17, wherein a wavelength of the light is between 0.1nm to 30 mm.
 58. An apparatus according to claim 18, wherein awavelength of the light is between 0.1 nm to 30 nm.
 59. A devicemanufacturing method comprising steps of: exposing an object to apattern using an exposure apparatus as recited in claim 18; anddeveloping the exposed object.
 60. An apparatus according to claim 18,further comprising: a member arranged in said first vacuum chamber, andcooled by a cooling mechanism.